JP2016185849A - Paper conveyance device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hardly cause damage of paper liable to occur by butting a tip of the paper against butting sections.SOLUTION: When a time T1 passes after a paper rear end is detected by a paper sensor normally (when a sheet of paper which is not overlapping paper is conveyed), a paper conveyance speed in a carry-in roll is lowered. On the other hand, a deceleration timing is accelerated when overlapping paper is conveyed. Concretely, deceleration is started when a time T2 (<time T1) passes after the paper rear end is detected by the paper sensor.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a sheet conveying device and an image forming system.

  Patent Document 1 discloses a process of switching back a sheet to the stapler side, butting the rear end of the sheet against a reference fence, and aligning the vertical position of the sheet.

JP 2011-251811 A

Positioning of the sheet can be performed by abutting the leading end of the conveyed sheet against an abutting portion located on the downstream side in the conveying direction. However, if the leading edge of the paper strongly hits the abutting portion, the paper may be damaged.
SUMMARY OF THE INVENTION An object of the present invention is to make it difficult to cause paper damage that may occur when the leading edge of a paper is abutted against an abutting portion.

The invention according to claim 1, the abutting portion where the leading edge of the conveyed paper abuts, the paper is conveyed toward the abutting portion, the leading edge of the paper is abutted against the abutting portion, and When the paper is decelerated at a predetermined deceleration start timing before the leading edge abuts against the abutting portion, and a plurality of overlapping sheets are conveyed toward the abutting portion, one sheet Compared to the case of transporting the paper toward the butting portion, the paper transport device includes a paper transport unit that increases the degree of deceleration when the deceleration start timing is advanced and / or decelerated.
According to a second aspect of the present invention, the preceding sheet that has been transported in advance is retained upstream of the sheet transporting unit, and the subsequent sheet that has been transported following the retained preceding sheet. The sheet conveying apparatus according to claim 1, further comprising: a conveying unit that conveys the sheet to the downstream side.
The invention according to claim 3 is an abutting portion where the leading edge of the conveyed paper abuts, a sheet is conveyed toward the abutting portion, and the leading edge of the paper is abutted against the abutting portion. The sheet is decelerated at a predetermined deceleration start timing before the leading edge abuts against the abutting part, and the length in the conveyance direction of the sheet conveyed toward the abutting part is set to a predetermined length. In the case of exceeding the predetermined length, the sheet conveying device includes a sheet conveying unit that increases the degree of deceleration when the deceleration start timing is advanced and / or decelerated compared to the case where the predetermined length is not exceeded.
According to a fourth aspect of the present invention, the sheet conveying means determines the deceleration start timing so that the deceleration start timing is advanced as the length of the sheet conveyed toward the abutting portion increases. The paper conveyance device according to claim 3, wherein the degree of deceleration is determined such that the degree of deceleration increases as the length of the paper increases.
The invention according to claim 5 includes an image forming apparatus that forms an image on a sheet, and a sheet conveying apparatus that conveys the sheet on which an image is formed by the image forming apparatus. 5. An image forming system, which is the paper transport device according to any one of claims 1 to 4.

According to the first aspect of the present invention, compared to the case where the deceleration start timing is not advanced or the degree of deceleration is not increased, it is possible to make the sheet less likely to be damaged due to the leading edge of the sheet hitting the abutting portion.
According to the second aspect of the present invention, the stagnation of the processing performed on the upstream side can be prevented as compared with the case where the preceding paper is retained and the preceding paper and the succeeding paper are not stacked and conveyed downstream.
According to the third aspect of the present invention, it is possible to make it difficult to cause damage to the paper due to the leading edge of the paper hitting the abutting portion as compared with the case where the deceleration start timing is not advanced or the degree of deceleration is not increased.
According to the fourth aspect of the present invention, it is possible to more reliably prevent the paper from being damaged than when the deceleration start timing and the deceleration degree are uniform.
According to the fifth aspect of the present invention, it is possible to provide an image forming system in which the paper is less likely to be damaged due to the leading edge of the paper hitting the abutting portion.

1 is a diagram illustrating an overall configuration of an image forming system to which the exemplary embodiment is applied. It is a figure explaining a processing unit. It is the figure which showed the apparatus structure downstream from the process unit. It is a figure explaining the structure of a saddle stitch bookbinding function part. It is a figure explaining the structure of a folding process mechanism. It is the figure which showed the paper conveyance speed in the carry-in roll. It is the figure which showed the paper conveyance speed in the carry-in roll in the case of raising the deceleration degree.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
<Description of Image Forming System 100>
FIG. 1 is a diagram illustrating an overall configuration of an image forming system 100 to which the exemplary embodiment is applied. An image forming system 100 shown in FIG. 1 performs post-processing on an image forming apparatus 1 such as a printer or a copying machine that forms a color image by an electrophotographic method, and a sheet S on which an image is formed by the image forming apparatus 1. A post-processing device 2 is provided. The post-processing device 2 has a function of transporting the paper S and can also be regarded as a paper transport device.

The image forming apparatus 1 is provided with an image forming unit 10 that forms an image on the paper S based on each color image data. The image forming unit 10 forms an image on the paper S using an inkjet method, an electrophotographic method, or the like.
The image forming apparatus 1 also includes an image reading unit 11 that reads an image from a document and generates read image data, a sheet supply unit 12 that supplies the sheet S to the image forming unit 10, and accepts an operation input from a user and a user. A comprehensive user interface 13 for presenting information to the user is provided.

  The image forming apparatus 1 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and the like, and is provided with a main control unit 14 that controls the operation of the entire image forming system 100.

  The post-processing apparatus 2 includes a processing unit 3 that performs trimming processing and the like on the paper S, a folding unit 4 that performs folding processing on the paper S that is carried in from the processing unit 3, and the paper S that has passed through the folding unit 4. A finisher unit 5 for performing final processing is provided.

  Further, the post-processing device 2 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and the like, and is provided with a sheet processing control unit 7 that controls each functional unit of the post-processing device 2. . In addition, a user interface (UI) 15 that receives an operation input from the user regarding post-processing is provided.

In the present embodiment, the configuration example in which the sheet processing control unit 7 is provided in the post-processing apparatus 2 has been described, but the sheet processing control unit 7 may be provided in the image forming apparatus 1. Further, the main control unit 14 may be configured to have the control function of the paper processing control unit 7.
Further, in the present embodiment, the configuration example in which the user interface 15 is provided in the post-processing apparatus 2 has been described, but the user interface 15 may be provided in the image forming apparatus 1. Further, the general user interface 13 may have a function of the user interface 15.

<Description of processing unit 3>
FIG. 2 is a diagram illustrating the processing unit 3.
The processing unit 3 is provided with a receiving port 301 for receiving the paper S conveyed from the image forming apparatus 1 and a discharge port 302 for discharging the paper S.
Further, the processing unit 3 is provided with a folding line forming device 303 for forming a folding line on the paper S, and a side edge removing device (top and bottom trimmer) 304 for removing the side edge of the paper S.

Further, the processing unit 3 is provided with a first paper transport path R1 through which the paper S passes. The first sheet transport path R1 starts from the receiving port 301 and moves toward the discharge port 302.
Further, the first paper transport path R1 is provided so as to pass through the folding line forming device 303 and the side edge removing device 304. Thus, in this embodiment, the paper S received at the receiving port 301 is folded. It goes to the muscle forming device 303 and the side edge removing device 304.

Further, the processing unit 3 is provided with a second paper transport path R2.
The second paper transport path R2 is provided so as to branch from the first paper transport path R1. Specifically, the second paper transport path R2 is branched from the first paper transport path R1 on the upstream side of the folding line forming device 303. Further, the second paper transport path R2 starts from the location connected to the first paper transport path R1 toward the discharge port 302.
The sheet S on which the crease is not formed and the side edge is not removed is directed to the discharge port 302 through the second sheet conveyance path R2.

Further, a plurality of transport rolls 48 are provided in the first paper transport path R1 and the second paper transport path R2 to transport the paper S located on these paper transport paths to the downstream side.
The transport roll 48 includes a drive roll 48A that is rotationally driven by a motor, and a driven roll 48B that rotates by receiving a driving force from the drive roll 48A.

  Furthermore, in the present embodiment, the first paper transport path R1 is branched on the downstream side of the side edge removing device 304, and the first paper transport path R1 includes the first branch path R11 and the second branch path R12. And are provided. The first branch path R11 and the second branch path R12 merge before the discharge port 302.

In the present embodiment, as will be described later, the folding process of the sheet bundle is performed by the folding knife 35a (see FIG. 4). This folding process takes time.
In such a case, it is necessary to stop the image forming operation in the image forming apparatus 1, which has higher processing efficiency than the folding processing, and the overall processing efficiency is lowered.

Therefore, in the present embodiment, when the folding process with the folding knife 35a is performed, the first branch path R11 and the second branch path R12 are used to suppress a decrease in processing efficiency.
Specifically, first, a sheet S conveyed from the upstream side (sheet S conveyed in advance) (hereinafter referred to as “preceding sheet S”) is sent to the first branch path R11, and this first The preceding sheet S is temporarily retained (standby) on the branch path R11.

When the succeeding sheet S (next sheet S) is sent, the succeeding sheet S is sent to the second branch path R12.
Thereafter, the preceding sheet S on the first branch path R11 and the subsequent sheet S on the second branch path R12 are sent out toward the discharge port 302.

As a result, the sheet S in which the preceding sheet S and the succeeding sheet S overlap (hereinafter referred to as “overlapping sheet S”) is supplied to the downstream side.
In the present embodiment, a process of aligning the leading edge of the preceding sheet S and the leading edge of the succeeding sheet S is performed before the discharge port 302. As a result, the overlapping sheets S are supplied to the downstream side with no deviation between the two sheets S included in the overlapping sheets S.

In the configuration of the present embodiment, the image forming operation in the image forming apparatus 1 can be continued even when the folding process with the folding knife 35a is performed.
Specifically, a second branch path R12 through which the subsequent sheet S can be fed is provided, and even when the folding process by the folding knife 35a is performed, by feeding the sheet S into the second branch path R12, The image forming operation in the image forming apparatus 1 can be continued. Thereby, the fall of processing efficiency is suppressed.

The crease forming device 303 and the side edge removing device 304 will be described.
The crease forming device 303 has an advancing member that advances from the side of the first paper transport path R1 toward the first paper transport path R1. Forming a crease. This crease is formed in a portion of the paper S where a knive knife 35a described later is pressed. Thereby, in this embodiment, the folding process by the folding knife 35a is performed more smoothly.

The side edge removing device 304 is a device that performs trimming, and removes a portion of the side edge (side edge along the first paper conveyance path R1) of the paper S.
Note that the waste generated by this removal is stored in a waste storage box 305 located below the side edge removing device 304.

<Device Configuration Downstream from Processing Unit 3>
FIG. 3 is a view showing a device configuration on the downstream side of the processing unit 3.
As shown in FIG. 3, a folding unit 4 is provided on the downstream side of the processing unit 3. The folding unit 4 is provided with a folding function unit 50 for folding the paper S such as an inner trifold (C fold) and an outer trifold (Z fold).

A finisher unit 5 is provided on the downstream side of the folding unit 4.
The finisher unit 5 is provided with a punch function unit 70 for punching (punching) the paper S such as 2 holes or 4 holes. Further, an end binding function unit 40 is provided that stacks a required number of sheets S to generate a sheet bundle, and performs staple binding (end binding) to the end of the sheet bundle.

Further, the finisher unit 5 accumulates a required number of sheets S to generate a sheet bundle, performs a binding process (saddle stitching process) on the central portion of the sheet bundle, and generates a booklet (booklet) ( A saddle stitch bookbinding function unit 30 is provided.
Further, the folding unit 4 and the finisher unit 5 are provided with a transport roll 48 for transporting paper. As described above, the transport roll 48 includes a drive roll 48A that is driven to rotate by a motor, and a driven roll 48B that rotates by receiving a driving force from the drive roll 48A.

<Description of Saddle Stitch Binding Function Unit 30>
FIG. 4 is a diagram illustrating the configuration of the saddle stitch bookbinding function unit 30.
The saddle stitching function unit 30 is provided with a compiling member 31 that is formed in a plate shape and arranged in a state inclined with respect to the vertical direction. The compiling member 31 accumulates a predetermined number of sheets S after image formation to generate a sheet bundle.

Further, a carry-in roll 39 for carrying the sheets S one by one into the compiling member 31 is provided. Further, a motor M that rotates the carry-in roll 39 is provided.
Further, an end guide 32 for supporting the sheet bundle on the compiling member 31 from below is provided. The end guide 32 can be moved along the compiling member 31.

In this embodiment, the paper S is transported (sent out) toward the end guide 32 by the carry-in roll 39 that functions as a part of the paper transport unit.
As a result, the leading edge of the paper S abuts against the end guide 32 that functions as an abutting portion. In the present embodiment, the leading edge of the paper S abuts against the end guide 32 so that the paper S is aligned in the transport direction.

  Further, in the saddle stitching function unit 30 of the present embodiment, the sheet alignment paddle 33 that urges the sheets S stacked on the compiling member 31 toward the end guide 32 and the compiling member 31 are stacked. A paper width alignment member 34 that aligns the paper S in the width direction of the paper S is provided. Further, a stapler 82 is provided that performs a binding process by passing a staple needle (not shown) through the bundle of sheets on the compiling member 31.

Further, the saddle stitching function unit 30 is provided with a folding processing mechanism 35 that performs a folding process on the sheet bundle subjected to the binding process.
The folding processing mechanism 35 is provided with a folding knife 35a. The folding processing mechanism 35 includes a motor or the like, and is provided with an advancing mechanism 35b that advances the folding knife 35a from the back surface side of the compiling member 31 toward the accommodation surface side.

  Further, the saddle stitching function unit 30 is provided with a sandwiching roll 36 composed of a pair of rolls. The sandwiching roll 36 sandwiches the sheet bundle that is started to be folded by the folding knife 35a and conveys the sheet bundle to the downstream side.

On the downstream side of the sandwiching roll 36, there are provided a discharge roll 38 for discharging the bundle of sheets that have been bound into a booklet, and a booklet stacking section 45 for stacking the bundle of sheets sent by the discharge roll 38.
Further, in the present embodiment, a paper sensor 92 that detects the rear end of the paper S carried into the compiling member 31 (the rear end of the paper S in the transport direction) is provided on the upstream side of the carry-in roll 39.

<Folding mechanism 35>
FIG. 5 is a diagram illustrating the configuration of the folding processing mechanism 35.
In the present embodiment, as described above, the folding processing mechanism 35 that performs the folding processing on the sheet bundle that has been subjected to the binding processing is provided.
The folding processing mechanism 35 is provided with a folding knife 35a and an advancing mechanism 35b that advances the folding knife 35a toward the sheet bundle.

Here, in the present embodiment, the folding knife 35 a advances to a position where the tip of the folding knife 35 a reaches the sandwiching roll 36.
As a result, a fold is formed in the sheet bundle, and the fold (folded portion) is further pressed from both sides by the sandwiching roll 36.

FIG. 6 is a diagram showing the sheet conveyance speed in the carry-in roll 39 (see FIG. 4).
In the present embodiment, usually (when one sheet S that is not the overlapping sheet S is conveyed), as shown in FIG. 6, the time T1 has elapsed since the sheet trailing edge was detected by the sheet sensor 92. Then, the paper conveyance speed in the carry-in roll 39 is reduced. This speed reduction is performed by controlling the motor M (see FIG. 4) by the paper processing control unit 7 (FIG. 3).

  In addition, in the present embodiment, the time when the time T1 has elapsed since the detection of the trailing edge of the paper by the paper sensor 92 is used as the deceleration start timing. At this deceleration start timing, the deceleration of the paper S is started, The sheet conveyance speed is changed from speed V1 to speed V2 (<speed V1).

As a result, when the leading edge of the sheet S hits the end guide 32, the conveyance speed of the sheet S becomes low. Thereby, damage to the paper S is suppressed.
In addition, in the present embodiment, the sheet S is decelerated at a predetermined deceleration start timing before the leading edge of the sheet S hits the end guide 32, and damage to the sheet S is suppressed.

On the other hand, when the overlapping sheets S are conveyed, the deceleration start timing is advanced.
Specifically, as shown in FIG. 6, when time T2 (<time T1) has elapsed since the detection of the trailing edge of the sheet by the sheet sensor 92, deceleration is started.

Here, as described above, the transport roll 48 provided in the folding unit 4 (see FIG. 3) includes a drive roll 48A that is rotationally driven by a motor, and a driven roll that rotates by receiving a driving force from the drive roll 48A. 48B.
When the stacked paper S passes through the transport roll 48 configured in this way, one of the papers S receives driving force from the driving roll 48A and is more likely to precede the other paper S. In this case, the paper length of the stacked paper S is larger than that when the single paper S is conveyed.

  Then, when the overlapped sheet S whose sheet length is increased in this way is decelerated at the same deceleration start timing as that of the normal sheet S (one sheet S), the overlapped sheet S becomes the end guide before the deceleration is performed. There is a possibility that the overlapped sheet S may abut against the end guide 32 during the deceleration. For this reason, in this embodiment, when the overlap sheet S is conveyed, the deceleration start timing is advanced.

  In the above description, the contact of the overlapped sheet S with the end guide 32 is suppressed by advancing the deceleration start timing. However, the contact can be suppressed by increasing the degree of deceleration. Further, the deceleration start timing may be advanced and the degree of deceleration may be further increased.

FIG. 7 is a diagram showing the sheet conveyance speed of the carry-in roll 39 when the degree of deceleration is increased.
As indicated by reference numeral 7A, when a single sheet S that is not the overlapping sheet S is conveyed, the time T1 has elapsed since the trailing edge of the sheet was detected by the sheet sensor 92, as described above. When the deceleration start timing is reached, the sheet S starts to be decelerated.

  On the other hand, when the overlapping sheets S are conveyed, the degree of deceleration is increased as indicated by reference numeral 7B. In other words, increase the deceleration rate per unit time. In this case, the conveyance speed decreases in a shorter time.

  In the above description, the deceleration start timing is determined according to one of the sheets S and the overlapping sheets S. However, a sensor for detecting the sheet length (the length in the transport direction of the sheet S) is installed and detected. The deceleration start timing and the deceleration degree may be determined based on the sheet length.

Specifically, for example, as shown in FIG. 4, the folding unit 4 is provided with a paper length detection sensor 93 for detecting the paper length.
The paper length detection sensor 93 grasps the paper length based on the required time from the passage of the leading edge of the paper S until the trailing edge of the paper S passes through the position opposite to the paper length detection sensor 93. More specifically, the sheet length is grasped based on the required time and the sheet conveyance speed.

  In this embodiment, when the paper length grasped by the paper length detection sensor 93 does not exceed a predetermined length, the speed is reduced after the time T1 (see FIG. 6) has passed since the trailing edge detection. I do. Further, when the paper length exceeds a predetermined length, deceleration is performed after time T2 (see FIG. 6) has elapsed since the trailing edge detection.

In addition, as indicated by reference numeral 7A in FIG. 7, when the paper length does not exceed the predetermined length, the degree of deceleration is moderate, and when the paper length exceeds the predetermined length, As indicated by reference numeral 7B, the degree of deceleration may be increased.
Furthermore, when the paper length exceeds a predetermined length, the deceleration start timing may be advanced to increase the degree of deceleration.

  Furthermore, instead of the choice of whether to accelerate the deceleration start timing or the choice of whether to increase the deceleration rate, the deceleration start timing and the degree of deceleration are determined according to the detected paper length. Also good. Specifically, the deceleration start timing is determined so that the deceleration start timing is advanced as the sheet length increases. Further, the degree of deceleration is determined so that the degree of deceleration increases as the sheet length increases.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Post-processing apparatus, 32 ... End guide, 39 ... Carry-in roll, 100 ... Image forming system, S ... Paper

Claims (5)

An abutting portion where the leading edge of the conveyed paper abuts,
The paper is transported toward the abutting portion, the leading edge of the paper is abutted against the abutting portion, and the paper is decelerated at a predetermined deceleration start timing before the leading edge abuts the abutting portion. When transporting a sheet of sheets in which a plurality of sheets are overlapped toward the abutting part, the deceleration start timing is advanced and compared with the case of conveying one sheet toward the abutting part. Paper conveying means for increasing the degree of deceleration when decelerating, and / or
A sheet conveying apparatus comprising:   The preceding sheet that has been transported in advance is retained upstream of the sheet transporting unit, and the retained preceding sheet and the subsequent sheet that has been transported are overlapped and transported downstream. The sheet conveying apparatus according to claim 1, further comprising a conveying unit. An abutting portion where the leading edge of the conveyed paper abuts,
The paper is transported toward the abutting portion, the leading edge of the paper is abutted against the abutting portion, and the paper is decelerated at a predetermined deceleration start timing before the leading edge abuts the abutting portion. When the length of the paper transported toward the abutting portion exceeds the predetermined length, the deceleration starts compared to the case where the length does not exceed the predetermined length. A paper conveying means for increasing the degree of deceleration when the timing is advanced and / or decelerated;
A sheet conveying apparatus comprising:   The sheet conveying means determines the deceleration start timing so that the deceleration start timing is earlier as the length of the sheet conveyed toward the abutting portion is larger and / or the length of the sheet is larger. The sheet conveying apparatus according to claim 3, wherein the degree of deceleration is determined so that the degree of deceleration increases.   5. A sheet according to claim 1, further comprising: an image forming apparatus that forms an image on a sheet; and a sheet conveying apparatus that conveys the sheet on which an image is formed by the image forming apparatus. An image forming system which is a conveying device.

Images